Can I use a table saw as a jointer? Yes, you absolutely can use a table saw as a makeshift jointer, but it requires specific jigs and careful setup. This method is often used by woodworkers who lack a dedicated jointer or need to size wide boards accurately.
Why Seek Alternatives to a Dedicated Jointer?
Most home workshops lack space or budget for a full-sized jointer. A jointer is vital for making wood flat on one face and square on one edge. These two faces are the foundation for all good woodworking. If you cannot joint, your projects will have gaps and wobbles.
Fortunately, the precise nature of a table saw allows for creative workarounds. By building or buying a specialized setup, you can achieve similar results to a dedicated machine. This process is about creating straight edges with a table saw reliably.
The Core Concept: Converting Table Saw to Jointer
A standard jointer works by spinning cutter heads against the wood, removing material evenly. A table saw, however, spins a blade that cuts across the grain (a ripping blade) or against the grain (a crosscut blade).
To mimic a jointer, we need two things:
1. A way to hold the wood perfectly flat against the table.
2. A way to use the fence to guide the wood past the blade at a precise, repeatable distance.
This is where the table saw jointer jig comes into play. It acts as a temporary, perfectly flat surface that rides against the fence, holding the workpiece steady.
Building Your Table Saw Jointer Jig
The success of flattening wood with a table saw relies entirely on the quality of your jig. This jig must be flat itself and must run perfectly parallel to the blade.
Materials Needed for the Jig
You will need strong, stable materials. Avoid soft woods like pine for the main body.
- Base Material: High-quality plywood (3/4 inch thick, Baltic Birch is excellent) or MDF. It must be perfectly flat.
- Fence Runner: A strip of solid hardwood or aluminum bar stock. This piece runs against your main table saw fence.
- Clamps/Fasteners: T-bolts, low-profile screws, or specialized clamping hardware.
Step-by-Step Jig Construction
This design creates a sled that rides along the table saw surface and locks against the existing fence. This is the essence of a DIY table saw jointer setup.
1. Prepare the Base Plate
Cut your plywood or MDF base. The width should be slightly less than the depth of your table saw throat plate, allowing the blade to protrude through the center. The length must be long enough to handle your longest expected workpiece comfortably.
2. Attach the Fence Runner
This is the most critical step for using table saw fence as jointer guide.
* Take your hardwood strip (the runner). It needs to be perfectly straight.
* Attach this runner securely to one long edge of the base plate.
* Ensure the runner is perfectly square (90 degrees) to the base plate. Any error here translates directly into a skewed edge on your wood.
3. Setting the Blade Height
The blade height determines the cut depth. For jointing, you want shallow passes, much like using a hand plane.
* Set the blade height so that only about 1/8 inch of the tooth tips stick above the top surface of the jig base. Too much blade exposure makes the setup dangerous and prone to tear-out.
4. Creating the Opening (The Cut Path)
Place the assembled jig onto the table saw.
* Turn the saw on (or use a marking technique) to see exactly where the blade cuts the jig.
* Carefully cut a narrow slot or remove a rectangular section of the jig base right where the blade exits. This opening must be just wide enough for the blade to pass through without touching the sides of the jig base.
5. Calibration: Achieving Flat Surfaces Table Saw
Before cutting lumber, you must square the jig to the blade.
- Place the jig on the table saw.
- Run a test piece of scrap wood across the blade. Check the resulting edge with a good square.
- If the edge is not square, you must adjust the fence runner attachment until the cut edge is 90 degrees to the table surface.
The Table Saw Jointing Technique for Squaring Lumber
Once the jig is built and calibrated, you are ready to perform jointing operations. This technique primarily focuses on creating one perfectly flat face and one perfectly square edge.
Phase 1: Creating the First Flat Face (The Reference Face)
A jointer creates a flat face by reference. When squaring lumber with a table saw, you need a reference surface on your workpiece that matches the flatness of your jig table.
If your board is warped or cupped, you must first find the flattest side and designate it as the reference face.
- Secure the Reference Face: Lay your board onto the jig base so that the reference face is firmly against the jig table.
- Fence Contact: Bring the board tightly against the jig’s hardwood fence runner. You want solid contact.
- The Pass: Turn the saw on. Gently push the entire assembly (jig and wood) through the blade. The blade will trim the top face of the board, making it parallel to the jig base.
Important Note: If your jig base is flat, and the board is held flat against it, the resulting top face of the board will be flat.
Phase 2: Creating the First Square Edge (The Reference Edge)
Now that you have one flat face, you need the adjacent edge to be 90 degrees to it.
- Reorient the Board: Flip the board over. The newly flattened face must now sit firmly against the jig base.
- Contact the Fence: Bring the original, flat side tightly against the jig fence runner. This ensures the new cut edge will be perfectly square to the reference face.
- The Pass: Push the assembly through the blade. This cut will make the edge perfectly square to the reference face.
You now have two adjacent surfaces that are flat and square to each other—the goal of jointing! This completes the table saw jointing technique for establishing your primary reference surfaces.
Flattening Wide Boards: Using the Table Saw as a Makeshift Jointer
If you need to flatten a board wider than a standard jointer capacity (or wider than your jig setup allows), you enter the territory of using the table saw for flattening wood with a table saw, often using winding sticks or a straight edge for reference.
This is less about jointing and more about controlled surfacing. This requires a very long, very straight reference edge (like a metal ruler or a high-quality level) and requires multiple passes.
The Sled Method for Surfacing
For boards wider than your jig, you can adapt the jig concept into a large surfacing sled, though this is complex and requires extreme care.
| Step | Action | Purpose |
|---|---|---|
| 1 | Identify high and low spots on the board. | Know where material needs removal. |
| 2 | Attach a perfectly straight guide rail (e.g., aluminum bar) to the board. | This rail will ride against the table saw fence. |
| 3 | Set the blade depth shallowly (1/8 inch). | Minimize stress and tear-out. |
| 4 | Run the board through, keeping the guide rail tightly against the fence. | The fence dictates the cut height relative to the table. |
| 5 | Repeat passes, referencing the newly cut flat area against the jig table or a secondary fence extension. | Slowly work down the high areas until the surface is level. |
This process is slow and requires patience. It’s the closest you can get to achieving flat surfaces table saw style without a thickness planer or a dedicated jointer.
Precision and Safety Considerations
When converting table saw to jointer, you are pushing the machine outside its primary design parameters. Safety and precision must be paramount.
Safety First
The forces involved when pushing a large jig and board through the blade are different from standard ripping.
- Jig Security: Ensure your jig is locked down well. If it shifts even slightly, your reference edge is ruined, and you risk kickback.
- Push Sticks and Blocks: Always use push sticks, push blocks, or push shoes, especially for the final sections of the cut. Never reach over the spinning blade.
- Dust Collection: Jointing creates fine, fluffy dust quickly. Ensure your dust collection is effective.
- Blade Choice: Use a high-quality, sharp, low-tooth-count ripping blade (24T or 40T). A standard high-tooth-count crosscut blade tends to chip and burn edges more easily during the scraping action of jointing.
Achieving Maximum Precision
The biggest enemy in this setup is vibration and poor alignment.
- Fence Parallelism: If your table saw fence is not perfectly parallel to the miter slot or the blade when set to zero, your resulting edge will not be square to the face. Check your saw’s alignment before building the jig.
- Jig Flatness: Any warp in your jig base will be transferred directly to the wood surface you are trying to flatten. Use the straightest materials possible.
- Consistent Feed Rate: A steady, even feed rate prevents the blade from digging in or lifting the wood, which causes uneven surfaces.
Comparison: Table Saw Jointing vs. Dedicated Jointer
It is important to note the limitations of this method. While effective for occasional use, it cannot fully replace a professional machine.
| Feature | Table Saw as Jointer (Jig Method) | Dedicated Jointer |
|---|---|---|
| Accuracy & Repeatability | Moderate to High, dependent on jig quality and operator skill. | Very High; factory calibrated for precision. |
| Capacity | Limited by the size and stability of the homemade jig. | Determined by machine width (6-inch, 8-inch, 12-inch capacity). |
| Surface Finish | Can leave slight marks from the blade teeth (requires light sanding). | Produces a glass-smooth finish ready for finishing. |
| Speed | Slow; requires careful setup and slow feeding. | Fast; handles material quickly and efficiently. |
| Setup Time | Significant initial time to build and calibrate the jig. | Minimal setup time; quick adjustments. |
The table saw method is excellent for achieving a perfectly square edge on a board that has already been surfaced by a planer or has one good face established. It is less ideal for taking severely warped material down to a flat state quickly.
Advanced Application: Using the Table Saw Fence Directly (For Fine Tuning)
Some experienced woodworkers attempt very fine adjustments without a full jig, relying solely on the existing table saw fence for using table saw fence as jointer guide for light cleanup passes.
This method generally involves:
1. Surfacing one face flat using a sled or planer first.
2. Setting the blade height to remove a tiny amount (e.g., 1/64 inch).
3. Holding the reference face very tightly against the table saw fence.
This is highly risky because the fence is usually not designed to take lateral pressure from the side of a wide board running against the grain path, which can cause deflection and ruin the squareness. For safer results and true jointing capabilities, the jig is highly recommended over attempting to use the fence alone.
Final Thoughts on the Makeshift Jointer Table Saw
Using a table saw to perform the functions of a jointer is a testament to resourceful woodworking. By carefully constructing a table saw jointer jig, woodworkers can reliably produce flat faces and square edges needed for accurate joinery. While it demands more setup time and attention to detail than a dedicated machine, the result—a solid foundation for your next project—is well worth the effort when space or budget is tight. Embrace the precision inherent in the table saw, respect the setup, and you can master the table saw jointing technique.
Frequently Asked Questions (FAQ)
Q1: Will this method work on heavily twisted wood?
A: Not effectively. The table saw setup, whether jig-based or sled-based, relies on the workpiece being held firmly against a flat reference surface (the jig table). If the wood is severely twisted or winding, you cannot hold it flat against the jig while simultaneously making a cut without causing severe tear-out or binding. You should first use a hand plane or a wide-belt sander to remove the worst of the twist before attempting flattening wood with a table saw.
Q2: How do I ensure my jig stays perfectly square to the blade over time?
A: Regular calibration is key. Every few sessions, or if you move the jig drastically, run a test piece through and measure the resulting edge against a trusted reference square. If you notice drift, you must tighten the fasteners holding the hardwood fence runner onto the jig base or adjust the setup until the cut edge is precisely 90 degrees to the table surface. Maintaining the integrity of your DIY table saw jointer setup requires vigilance.
Q3: Can I skip the jig and just run the wood against the fence?
A: This is generally advised against. The main table saw fence is designed to resist forces pushing perpendicular to the blade (during ripping). When jointing, the side pressure is applied parallel to the fence but pushing the workpiece down onto the table. Without a stable jig backing up the workpiece, the board can easily lift, wobble, or chatter against the fence, leading to an uneven, non-square edge—the opposite of achieving flat surfaces table saw style.
Q4: What size lumber can I realistically process this way?
A: Realistically, this setup works best for narrower stock, perhaps up to 8 or 10 inches wide, depending on the width of your table saw deck. Very wide boards (12+ inches) become unstable when trying to keep the entire length flat against the jig base as they pass through the blade area. For wider boards, you might need to make several passes, essentially breaking the board down into narrower sections that you then rejoin later.